2 clients have a cifs share set up for them for collaboration between 2 users.
One of the users approached me and said it seemed like their edits are not being seen by the other person.
I confirmed this by comparing file sizes, time stamps and permissions which are the same when seen from either account/computer
However when the files are opened the contents are different. I verified the files are not opened by either user. Then had them open the files using the same program in the same way. The contents seen are different.

I"m about to go thru the backups to compare when the edits were done, but why would 2 computers not see the content when each are accessing the same file.

Here are client details.

host1
3.10.0-693.el7.x86_64,
7.5.1804

host2
3.10.0-862.el7.x86_64
7.5.1804

These clients can't be rebooted for the next 10days as the users are research folks working on projects.

First check the sha256sum output from each client and if the host is Linux or Windows check it from there.

If they all match - the issue is in the client program, and you can dry run an update (client programm only) on the older client and if no system dependencies required - you can upgrade and ask the end-user to try again.